JP2019052197A - UV curable silicone resin composition having heat resistance and optical semiconductor device using the same - Google Patents

Abstract

The present invention relates to an ultraviolet ray that has heat resistance and does not deteriorate even when placed under high temperature for a long time, and as a result, has a heat resistance that causes little reduction in brightness of the LED when used in an LED sealant. A curable silicone resin composition and an optical semiconductor device using the same are provided.
An organovinylpolysiloxane (A) having at least two silicon-bonded alkenyl groups that react with SiH groups in one molecule and an organohydrogenpolysiloxane (B) having at least two SiH groups in one molecule. And a photoactive hydrosilylation reaction catalyst (C), and a rare earth-containing organopolysiloxane compound as a heat resistance imparting agent (D), and a heat-resistant ultraviolet curable silicone resin composition, This is an optical semiconductor device using this.
[Selection figure] None

Description

  The present invention relates to an ultraviolet curable silicone resin composition having heat resistance, which does not deteriorate even when placed at a high temperature for a long time and does not generate cracks, and an optical semiconductor device using the same.

Conventionally, an activated energy ray-curable silicone composition capable of efficiently forming a negative pattern with high accuracy has been proposed (Patent Document 1). The activated energy ray-curable silicone composition is (1) the following:
(A) an organopolysiloxane having at least two alkenyl groups bonded to a silicon atom in one molecule, and an organohydrogenpolysiloxane or hydrosilane compound having at least two hydrogen atoms bonded to a silicon atom in one molecule; A mixture thereof, and (b) at least one selected from the group consisting of an alkenyl group bonded to a silicon atom and an organopolysiloxane having a hydrogen atom bonded to a silicon atom in the same molecule, (2) a hydrosilylation reaction It is an activated energy ray-curable silicone composition containing a platinum catalyst for promotion, (3) a reaction inhibitor for platinum catalyst, and (4) an organic peroxide.

  However, when the silicone resin composition is left at a high temperature of 200 ° C. or higher for a long time, the cured product may be cracked, and for example, as a sealant for an optical semiconductor element (hereinafter referred to as LED). When used, there is a problem that the luminance of the LED may decrease.

JP 2006-177899 A

  The problem to be solved by the present invention is that it has heat resistance and is not deteriorated even when placed under high temperature for a long time, so that cracks do not occur. It is an object to provide an ultraviolet curable silicone resin composition having a low heat resistance and an optical semiconductor device using the same.

In order to solve the above-mentioned problem, the invention according to claim 1 is an organovinylpolysiloxane (A) having at least two silicon-bonded alkenyl groups that react with SiH groups in one molecule;
An organohydrogenpolysiloxane (B) having at least two SiH groups in one molecule;
A photoactive hydrosilylation catalyst (C);
As a heat resistance imparting agent (D),
An organopolysiloxane (D1) having a viscosity at 25 ° C. of 10 to 10,000 mPa · s;
Cerium carboxylate represented by the general formula (R ₁ COO) _n M (R ₁ is the same or different monovalent hydrocarbon group, M is a rare earth element mixture mainly composed of cerium, n = 3 or 4) D2)
A titanium compound (D3) represented by the general formula (R ₂ O) ₄ Ti (R ₂ is the same or different monovalent hydrocarbon group);
A rare earth-containing organopolysiloxane compound obtained by heat treatment at a temperature of 250 ° C. or higher;
An ultraviolet curable silicone resin composition having heat resistance is provided.

  According to a second aspect of the present invention, there is provided an optical semiconductor device, wherein the optical semiconductor element is sealed with the cured product of the first aspect.

  The ultraviolet curable silicone resin composition having heat resistance of the present invention has the effect that there is no decrease in physical properties and no occurrence of cracks even when placed at a high temperature for a long time, resulting in a decrease in the brightness of the LED. There is no effect. The optical semiconductor device according to claim 2 has an effect that there is no decrease in luminance as a result.

  Hereinafter, the ultraviolet curable silicone resin composition having heat resistance according to the present invention will be specifically described.

<Organovinylpolysiloxane (A)>
Organovinylpolysiloxane (A) has at least two silicon-bonded alkenyl groups that react with SiH groups in one molecule, and these alkenyl groups are vinyl group, allyl group, propenyl group, isopropenyl group, butenyl group, isobutenyl group. Or a carbon-carbon double bond such as a hexenyl group. Examples of the organopolysiloxane (A) include those in which the main chain is a repeating unit of diorganosiloxane and the terminal has a triorganosiloxane structure, and may have a branched or cyclic structure. Examples of the organo group bonded to silicon in the terminal or repeating unit include a methyl group, an ethyl group, and a phenyl group. Specific examples include methyl vinyl polysiloxane having vinyl groups at both ends.

<Organic hydrogen polysiloxane (B)>
The organohydrogenpolysiloxane (B) has at least two SiH groups in one molecule, and contains two or more SiH groups in at least a terminal or repeating structure. The content of hydrogen atoms bonded to silicon atoms is preferably 1.0 mmol / g to 20.0 mmol / g, and if it is 1.0 mmol / g or more, curability is improved and hardness is easily obtained. . When the content of hydrogen atoms exceeds 20.0 mmol / g, tackiness is likely to occur on the surface of the cured product. In order to obtain good hardness, the hydrogen atom content ratio is more preferably 1.5 mmol / g or more. In order to make it difficult for tackiness to occur, the hydrogen atom content is more preferably less than 10.0 mmol / g. Examples of the organo group bonded to the silicon atom include a methyl group, an ethyl group, and a phenyl group. The organohydrogen polysiloxane may be, for example, linear or branched, and specific examples include methylhydrogen polysiloxane.

<Photoactivated hydrosilylation reaction catalyst (C)>
The photoactivated hydrosilylation reaction catalyst (C) is added to promote the hydrosilylation reaction of the component (A) and the component (B), and has a known photoactive metal having catalytic activity for the hydrosilylation reaction. , Metal compounds, metal complexes, and the like can be used. In particular, a photoactive platinum group metal catalyst or nickel catalyst is preferable. As the photoactive platinum group metal catalyst, platinum-based, palladium-based, and rhodium-based catalysts can be used, and among these, platinum-based catalysts are preferable. Examples of the photoactive platinum-based catalyst include β-diketonate platinum complex catalysts such as trimethyl (acetylacetonato) platinum complex, trimethyl (3,5-heptanedionate) platinum complex, trimethyl (methylacetoacetate) platinum complex, Bis (2,4-pentanedionato) platinum complex, bis (2,4-hexandionato) platinum complex, bis (2,4-heptanedionato) platinum complex, bis (3,5-heptaneedionato) platinum complex, bis ( Examples thereof include 1-phenyl-1,3-butanedionato) platinum complex and bis (1,3-diphenyl-1,3-propanedionato) platinum complex. Also, (methylcyclopentadienyl) trimethylplatinum can be used. As the photoactive nickel-based catalyst, for example, bis (2,4-pentanedionato) nickel complex can be used. These may be used alone or in combination of two or more. Among them, the catalyst used in the curing method of the present invention is preferably bis (2,4-pentanedionato) platinum complex or the commonly used name bis (acetylacetonato) platinum (II).

  The compounding amount of the photoactivated hydrosilylation reaction catalyst (C) component may be an effective amount, and is usually 0.1 to 0.1 in terms of platinum group metal (weight basis) with respect to the total amount of the components (A) and (B). 1,000 ppm, preferably 0.5 to 200 ppm. Within the above range, the ultraviolet curable silicone resin composition can be cured in a short time.

<Heat resistance imparting agent (D)>
This invention contains the heat resistance imparting agent (D) which suppresses the physical property change of the silicone resin in a high temperature environment other than the said (A) component, (B) component, and (C) component. The heat resistance-imparting agent (D) includes an organopolysiloxane (D1) having a viscosity at 25 ° C. of 10 to 10,000 mPa · s,
Cerium carboxylate represented by the general formula (R ₁ COO) _n M (R ₁ is the same or different monovalent hydrocarbon group, M is a rare earth element mixture mainly composed of cerium, n = 3 or 4) D2)
A titanium compound (D3) represented by the general formula (R ₂ O) ₄ Ti (R ₂ is the same or different monovalent hydrocarbon group);
It is a rare earth-containing organopolysiloxane compound obtained by heat treatment at a temperature of 250 ° C. or higher.

  The organopolysiloxane (D1) may be any conventionally known organopolysiloxane having a viscosity of 10 to 10,000 mPa · s at 25 ° C., which is substantially composed of repeating diorganopolysiloxane units (linear structure). It is a straight-chain or branched one that keeps liquid at room temperature. The organic group bonded to the silicon atom (that is, an unsubstituted or substituted monovalent hydrocarbon group) is specifically an alkyl group such as a methyl group, an ethyl group, a propyl group, or a butyl group; a vinyl group, an allyl group An alkenyl group such as a phenyl group or a tolyl group; a cycloalkyl group such as a cyclohexyl group; or a group in which part or all of the hydrogen atoms bonded to these carbon atoms are substituted with a halogen atom, a cyano group, or the like; For example, it is selected from chloromethyl group, fluoropropyl group, cyanomethyl group and the like. As the organopolysiloxane (D1), the molecular chain terminal is a trialkylsiloxy group such as a trimethylsiloxy group, an alkenyldialkylsiloxy group such as a vinyldimethylsiloxy group, a dialkenylalkylsiloxy group such as a divinylmethylsiloxy group, a trivinyl Examples thereof include those blocked with a triorganosiloxy group such as a trialkenylsiloxy group such as a siloxy group, a hydroxyl group or an alkoxy group. Moreover, the mixture of these various organopolysiloxane may be sufficient. The viscosity of the organopolysiloxane (D1) component is 10 to 10000 mPa · s, preferably 50 to 1000 mPa · s at 25 ° C. When the viscosity is 10 mPa · s or less, the amount of siloxane evaporation at a high temperature tends to increase and the weight change increases, so the heat resistance tends to decrease. On the other hand, when it exceeds 10,000 mPa · s, mixing with a cerium compound, which will be described later, is not performed smoothly, so that the heat resistance is likely to be lowered.

The carboxylic acid salt of cerium as the component (D2) has the general formula:
(R ₁ COO) _n M
Where R ₁ is the same or different monovalent hydrocarbon group, M is a rare earth element mixture mainly composed of cerium, 2-ethylhexanoic acid, naphthenic acid, oleic acid, lauric acid, stearin Illustrative are cerium salts such as acids. This cerium carboxylate is preferably used as an organic solvent solution from the viewpoint of ease of handling and compatibility with titanium of the following (D3) component or zirconium compound of the (D4) component. Examples of the organic solvent include petroleum solvents such as standard solvent, mineral spirit, ligroin and petroleum ether, and aromatic solvents such as toluene and xylene.

  Component (D2) is added in such an amount that the amount of cerium is 0.05 to 5 parts by weight, preferably 0.1 to 3 parts by weight, based on 100 parts by weight of component (A). When the amount of cerium is less than 0.05 parts by weight, the expected heat resistance cannot be obtained. On the other hand, when the amount is more than 5 parts by weight, the cerium compound becomes non-uniform in the component (D1), and the predetermined heat resistance cannot be obtained.

The titanium compound as the component (D3) has the general formula:
(R ₂ O) ₄ Ti
Indicated by Here, each R ₂ is independently a monovalent hydrocarbon group, preferably an alkyl having 1 to 30 carbon atoms such as an isopropyl group, n-butyl group, stearyl group, octyl group, etc., preferably 1 to 20 carbon atoms. And Ti is titanium. Such a compound is exemplified by tetraalkoxytitanium, but may be a partially hydrolyzed condensate thereof.

  The heat resistance imparting agent (D) component is obtained by mixing the components (D1) to (D3) and then heat-treating at a temperature of 250 ° C. or higher, but a uniform composition when the heating temperature is less than 250 ° C. When the temperature exceeds 310 ° C., the thermal decomposition rate of the component (D1) increases, so that the treatment is preferably performed at 250 to 310 ° C.

  Component (D) is added in an amount of 0.01 to 5 parts by weight, preferably 0.05 to 4 parts by weight, per 100 parts by weight of component (A). When the added amount of component (D) is less than 0.01 parts by weight, the effect of improving the heat resistance at high temperature is not seen, and conversely, when the amount exceeds 5 parts by weight, the transparency of the composition decreases. There is.

  The structure of the rare earth-containing organopolysiloxane compound is such that the cerium carboxylate (D2) before the heat treatment is a carboxylate of a mixture of rare earth elements mainly composed of cerium, and the rare earth-containing organopolysiloxane obtained by the heat treatment. Since the siloxane compound is not a simple substance, it is difficult to isolate and identify each trace component, and it is impossible to identify it by its structure. Moreover, it is difficult to separate the rare earth-containing organoorganopolysiloxane as a mixture, and the rare earth-containing organopolysiloxane compound obtained by heat treatment cannot be directly specified by its characteristics. Therefore, the rare earth-containing organopolysiloxane compound has a situation where it is impossible or almost impractical to “directly identify the product by its structure or characteristics at the time of filing”.

  The ultraviolet curable silicone resin composition having heat resistance of the present invention is cured by mixing the components (A) to (D). In that case, it can divide | segment and mix into the main ingredient part which consists of (A) component, (C) component, and (D) component, and the hardening | curing agent part which consists of (B) component.

<Other optional components>

  In the present composition, as other optional components, alkyne alcohols such as 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, ethynylcyclohexanol; Enyne compounds such as 3-penten-1-yne and 3,5-dimethyl-3-hexen-1-yne; 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane, compounds having an aliphatic unsaturated bond such as 1,3 divinyltetramethyldisiloxane, reactions of benzotriazole, etc. An inhibitor may be contained. This reaction inhibitor has a content that does not inhibit curability and is 0.0001 to 1 part by weight with respect to a total of 100 parts by weight of component (A), component (B), component (C), and component (D). It is preferable to be within the range.

  Moreover, in order to improve the adhesiveness, this composition may contain an adhesiveness imparting agent. As this adhesion-imparting agent, an epoxy group- or alkoxy group-containing organosilicon compound, or a condensate thereof may be used. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a methoxyethoxy group, and a methoxy group is particularly preferable. The group other than the alkoxy group bonded to the silicon atom of the organosilicon compound includes a substituted or unsubstituted monovalent hydrocarbon group such as an alkyl group, an alkenyl group, an aryl group, an aralkyl group, and a halogen-substituted alkyl group; 3 -Glycidoxyalkyl groups such as glycidoxypropyl group and 4-glycidoxybutyl group; epoxies such as 2- (3,4-epoxycyclohexyl) ethyl group and 3- (3,4-epoxycyclohexyl) propyl group Cyclohexylalkyl group; epoxy group-containing monovalent organic group such as oxiranylalkyl group such as 4-oxiranylbutyl group and 8-oxiranyloctyl group; acrylic group-containing monovalent organic group such as 3-methacryloxypropyl group Group; a hydrogen atom is exemplified. In order to improve adhesiveness while maintaining heat resistance, for example, tris (3-trimethoxysilylpropyl) isocyanurate is preferably used. The organosilicon compound preferably has a group capable of reacting with the component (A) or the component (B), and specifically has a silicon atom-bonded alkenyl group or a silicon atom-bonded hydrogen atom. Moreover, since it can provide favorable adhesiveness to various types of substrates, the organosilicon compound preferably has at least one epoxy group-containing monovalent organic group in one molecule.

  Moreover, in order to improve heat resistance further in this composition, you may contain antioxidant. As the antioxidant, those generally used can be used. For example, in addition to hindered phenols, phosphorus-based, hindered amine-based and thioether-based antioxidants may be mentioned. The content of the antioxidant is preferably in the range of 0.0001 to 1 part by weight with respect to 100 parts by weight as a total of the components (A), (B), (C) and (D). .

  In addition, this composition contains calcium carbonate, cinnabar sand, talc, carbon black, titanium oxide, zinc oxide, kaolin, silicon dioxide, melamine for viscosity adjustment and hardness adjustment as long as the object of the invention is not impaired. May contain inorganic fillers such as organic fillers, reinforcing materials such as glass fibers to reinforce cured resins, and hollow bodies such as shirasu balloons and glass balloons to reduce weight and adjust viscosity it can. In addition, antioxidants, organic pigments, fluorescent pigments, corrosion inhibitors, and the like can be used as appropriate.

  In the optical semiconductor device according to claim 2 of the present invention, an optical semiconductor element such as an optical semiconductor (LED) is sealed with a cured product of the heat-resistant ultraviolet curable silicone resin composition according to claim 1. It is an optical semiconductor device.

  Next, the ultraviolet curable silicone resin composition having heat resistance according to the present invention will be described in detail with reference to Examples and Comparative Examples.

<Preparation of heat resistance imparting agent (D)>
As an organopolysiloxane (D1) having a viscosity of 10 to 10,000 mPa · s at 25 ° C., a linear dimethylpolysiloxane having both ends sealed with trimethylsiloxy groups and having a viscosity of 100 mP · s / 25 ° C. As cerium carboxylate (D2), 2-ethylhexanoic acid rare earth terpene solution rare earth OCTOATE 6% (rare earth element content 6% by weight, manufactured by DIC), titanium compound (D3) as titanium tetra Using normal butoxide (titanium content 14% by weight), the components (D2) and (D3) were mixed in the formulation shown in Table 1, and the mixture was added to the component (D1) with stirring. Thereafter, the terpene was volatilized by heating while circulating nitrogen gas. Then, it heated at 300 degreeC for 1 hour, stirring, and prepared the brown and transparent heat resistance imparting agent (D).

<Examples and Comparative Examples>
And organovinyl polysiloxane with both molecular chain ends are linear dimethylpolysiloxane having a weight average molecular weight of 70,000 which is blocked with M ^Vi group (A-1), both molecular chain terminals blocked with M ^Vi group Organovinylpolysiloxane (A-2) which is a linear dimethylpolysiloxane having a mass average molecular weight of 35,000, and linear dimethylpolysiloxane having a mass average molecular weight of 114,000 in which both ends of the molecular chain are blocked with M ^Vi groups. Organovinylpolysiloxane (A-3) which is a siloxane and organovinylpolysiloxane (A-4) which is a branched dimethylpolysiloxane having a mass average molecular weight of 5,400, which is blocked with M ^Vi groups and contains Q units. a), the terminal is a branched-chain dimethylpolysiloxane having a weight average molecular weight of 2,000 containing Q units are blocked with M ^Vi group And Lugano vinyl polysiloxane (A-5), are blocked with both molecular chain terminals M ^H group, D ^Me units, organohydrogen a linear dimethylpolysiloxane having a weight average molecular weight of 10,400 containing D ^H units Siloxane (B-1), organohydrogenpolysiloxane (B-2), which is a branched dimethylpolysiloxane having a weight average molecular weight of 1,500, which is blocked with a terminal ^MH group and contains Q units, and photoactive hydrosilylyl Using bis (2,4-pentanedionato) platinum complex as the oxidization reaction catalyst (C), and using the heat resistance imparting agent (D) prepared above as the heat resistance imparting agent (D), Table 2 The ultraviolet curable silicone resin composition which has the heat resistance of an Example and a comparative example was obtained by mixing | blending.

M ^Me unit: (CH ₃ ) ₃ SiO _1/2
M ^Vi unit: (CH ₃ ) ₂ (CH ₂ = CH) SiO _1/2
^MH unit: (CH ₃ ) ₂ HSiO _1/2
D ^Me unit: (CH ₃ ) ₂ SiO _2/2
^DH unit: (CH ₃ ) HSiO _2/2
Q unit: SiO _4/2

<Evaluation items and evaluation methods>

<Durometer hardness>
The ultraviolet curable silicone resin compositions of Examples and Comparative Examples were poured into a 4 cm × 6 cm × 2 mm thick mold and irradiated with UV for 1 minute with a UV irradiator EXECURE-4000 (manufactured by HOYA), and then for 1 hour. It cools to 23 degreeC and removes from a metal mold | die, and the hardened | cured material of an Example and a comparative example is produced. Each cured product having a thickness of 2 mm was superposed to a thickness of 6 mm, and the hardness was measured with a type A durometer defined in JIS K 6253 to obtain an initial durometer hardness. Thereafter, the cured product was allowed to stand in an oven at 270 ° C. for 20 hours, 50 hours, and 200 hours, gradually cooled to 23 ° C. after the passage of each time, and the durometer hardness was measured in the same manner.

<Weight change rate>
The ultraviolet curable silicone resin compositions of Examples and Comparative Examples were poured into a 4 cm × 6 cm × 2 mm thick mold and irradiated with UV for 1 minute with a UV irradiator EXECURE-4000 (manufactured by HOYA), and then for 1 hour. It cools to 23 degreeC and removes from a metal mold | die, and the hardened | cured material of an Example and a comparative example is produced. This weight is measured and used as the initial weight. Thereafter, the cured product is left in an oven at 270 ° C. for 20 hours, 50 hours, and 200 hours, gradually cooled to 23 ° C. after the passage of each time, and the weight is measured to obtain the weight after heating. A value obtained by dividing the weight after heating by the initial weight was calculated as a weight change rate (%).

<Crack>
The ultraviolet curable silicone resin compositions of Examples and Comparative Examples were poured into a 4 cm × 6 cm × 2 mm thick mold and irradiated with UV for 1 minute with a UV irradiator EXECURE-4000 (manufactured by HOYA). It cools to 23 degreeC and removes from a metal mold | die, and the hardened | cured material of an Example and a comparative example is produced. Each cured product having a thickness of 2 mm was superposed to a thickness of 6 mm, and the hardness was measured with a type A durometer defined in JIS K 6253 to obtain an initial durometer hardness. Thereafter, the cured product was allowed to stand in an oven at 270 ° C. for 20 hours, 50 hours, and 200 hours, and it was visually confirmed whether or not cracks had occurred in the cured product after each time.

<Evaluation results>
The evaluation results are shown in Table 3.

Claims (2)

An organovinylpolysiloxane (A) having at least two silicon-bonded alkenyl groups that react with SiH groups in one molecule;
An organohydrogenpolysiloxane (B) having at least two SiH groups in one molecule;
A photoactive hydrosilylation catalyst (C);
As a heat resistance imparting agent (D),
An organopolysiloxane (D1) having a viscosity at 25 ° C. of 10 to 10,000 mPa · s;
Cerium carboxylate represented by the general formula (R ₁ COO) _n M (R ₁ is the same or different monovalent hydrocarbon group, M is a rare earth element mixture mainly composed of cerium, n = 3 or 4) D2)
A titanium compound (D3) represented by the general formula (R ₂ O) ₄ Ti (R ₂ is the same or different monovalent hydrocarbon group);
A rare earth-containing organopolysiloxane compound obtained by heat treatment at a temperature of 250 ° C. or higher;
An ultraviolet curable silicone resin composition having heat resistance, comprising: An optical semiconductor device, wherein an optical semiconductor element is sealed with the cured product according to claim 1.